Environmental friendly package development by using copper wirebonding

This paper focuses on the 1.0 mil Cu wire development and its reliability performance mainly at component level of a BGA wire bond package which consists of 2 metal layer organic substrate more than 500 pin counts. This paper covers package reliability tests such as THB (Temperature and Humidity Biased test), unbiased HAST, TCB (temperature cycling B), high temperature storage tests on BGA laminate with 1.0 mil 4N bare Cu wire. Selection of best package BOM was based on component reliability test and also assembly process data collected during the evaluation. Therefore selection of BOM is not solely based on reliability performance but also its process feasibility and manufacturability. Comprehensive experimental analysis has been carried out to determine the bill of materials for the most robust Cu wire bonding process and reliability performance. Failure analysis on the unbiased HAST failure unit was carried out to understand the failure mechanism and benchmark to the industrial finding. Final reliability validation based on the selected BOM and process condition was conducted and results have been covered in this paper. In addition, comprehensive ongoing reliability monitoring program and yield monitoring have been established to ensure flawless production implementation and package reliability of Altera´s Cu wirebond BGA laminate package.